Power hammer



March 8,1927. v 1,620,525

. F. H. DERBY POWER HAMMER Filed Oct. 26. 1922 2 Sheets-Sheet 1 F. H.DERBY M arch 1927. 1,620,525

POWER HAMMER Filed Oct. 26. 1922 2 sheets-sheet 2 4 E llllllwmgi n 40Patented Mar. 8, 1927.

' U N D AT ES 1,620,525 PATENT v orrrca.

FRANK H. DERBY, OIE ERIE, PENNSYLVANIA, ASSIGNOR TO ERIE FOUNDRYGQMPANY, OF ERIE, PENNSYLVANIA, A OORPORATIQN F PENNSYLVANIA.

POWER HAMMER.

This invention is designed to improve power hammers, particularly powerhammers in which there is a lifting device automatically thrown into andout of engagement by the action of the hammer; With devices'as commonlyused the hammer delivers a uniform blow and the return or lifting strokeis brought about with the same relative timing. In order to vary theaction of the hammer and particularly to obtain the benefit of therebound in pickingup the hammerhead to retract it, it is desirable tohave the means for throwing into engagement the lifting mechanism soadjustable that the timing may be varied to suit the conditions underwhich the hammer is used and to have this means adjustable while thehammer is actually in operation. WVith the present invention this isaccomplished. Features of the invention will appear from thespecification and claims.

The invention is illustrated in the accom-- panying drawings as followsFig. 1 shows a front elevation of the hamnier.

Fig. 2 a section on the line 2-2 in Fig. 1.

Fig. 3 an enlarged section on the line 33 in Fig. 1.

Fig. l an enlarged front elevation of the tripping mechanism.

1 marks the base, 2 the anvil, 3 the side 4 frames, 4.- the hammerguides, 5 the hammer head, and 6 friction lifting bars preferably ofwood. The lifting bars extend upwardly between the friction pulleys 7and 8, these pulleys being mounted on shafts 9 and 10 driven by pulleys11 and 12. The shaft 9 is journaled in a bearing 13 and the shaft 10 ina bearing 14. These bearings are carried on posts 15 on a cap plate 16.The bearing 14 is arranged in an eccentric 17 Lever arms 18 extend fromthe eccentric and a trip rod 19 is pivotally connected with the leverarms 18. So far the structure is one commonly used. As the ee centric 17is operated the friction pulleys 7 and 8 are thrown into and out offrictional engagement with the bars 6 so as to alternately lift thehammer and drop it.

The releasing trip mechanism is as follows: A lever 20 is pivotallymounted on the rod 19 by means of a pin 21. The lever is provided with asocket 22 which engages a pin 23 on the frame. The inner end of a recess37 in the latch block.

Application filed October 26, 1922. Serial 110.5%,087.

the leveris in the path of the pin 2% on the hammer head. As the hammerreaches its upper position the pin 2& engages the lever, lifts the rod19 and this swings the eccentric 17' soas to disengage the pulleys"? and8, thus tripping the hammer.

The lower end of the rod 19 extends through a guide 25 secured to theframeand as the rod 19 is lifted the ratchet shoulder 26 is caught bythelatch block 28 and thus holds the rodin the upper position until thehammer reaches the lower position and actuates the latch. The shoulderis the form of aslottedblock and is clamped by screws 27 on the rod 19.The block 28 slides in a guide 29 on the frame and is held in the guideby a plate 30 secured to the frame. The latch block is forced forward bya spring 31. A latch bar 32 extends forwardly from the latch block andhas a cam or bevelled end 33 which extends into the path of a cam 3% onthe hammer head so that as the hammer descends the cam operating on thelatch bar forces the latch block outwardly and thus releases the latchshoulder 26 and allows the rod 19 to drop so as to throw the pulleys 7and 8 into engagement. The latch bar 32 is secured on the frame by meansof the guiding plate 35 which is secured to the frame. The latch bar hasan ear 36 at its outer end which extends into A screw 38 extends throughthe ear and is provided with collars 39 at each side of the ear 36 sothat the screw is free to rotate in the ear but is locked against axialmovement rela tively thereto. The screw extends into the latch block sothat as the screw is turned in and out of the latch block it carries thelatch block 28 inwardly, or outwardly, and thus varies the time that thelatch block 28 is moved from under the block 26 and the time in whichthe retracting movement of the mechanism starts. The screw has ashoulder dO which engages the outer face of the bushing l0 and thebushing is locked in place on the frame by a cover plate 41. Thisshoulder forms a positioning stop, therefore, for the latch block thespring 31 forcing the screw forward until stopped and positioned by theshoulder -10. When the cam 33 is engaged and forced to the rear the car36 operating on the shoulder 39 forces the screw outwardly, the screwreturning under the influence of the spring to the position with thestop against the bushing 40. The outer end of the screw has a perforatedprojection 42 by means of which the screw may be turned so as to adjustthe latch bar.

It will be noted that the latch bar may be adjusted during the activeoperation of the hammer so that the operator may adjust the hammer so asto have it delicately respond to the conditions required.

A hand-operated lever 43 is pivoted at it and is adapted to lift the rod19 in starting the hammer.

What I claim as new is 1. In a power hammer, the combination of a hammerhead; a power-actuated lift device for the head; means throwing saiddevice into and out of lifting relation with the head; a latch shoulderon the means; a latch comprising a sliding cam bar having one end in thepath of the head; an adjusting screw;

a connection between the screw and bar maintaining a fixed axialrelation between the bar and screw; a latch block on the screw inoverlapping latching relation with said shoulder and adjustablerelatively thereto by the screw to vary the timing of the means; and astop maintaining a constant relation between the bar and head as theblock is adjusted by the screw 2. In a power hammer, the combination ofa hammer head; a power-actuated lift device for the head; means throwingsaid device into and out of lifting relation with the head comprising atrip rod; a shoulder on the trip rod; a sliding cam bar having one endin the path of the head; a shoulder on the cam bar; a screw extendingthrough the shoulder; stops on the screw locking the shoulder with thescrew; a latch block arranged on the screw and adjustable thereby andco-operating with the shoulder on the trip rod; a stop for the screw;and a coil spring around the screw forcing the block and cam bar totheir forward position.

In testimony whereof I have hereunto set my hand.

FRANK H. DERBY.

